A modified back-to-back HVDC system for 36-pulse operation

Recently, back-to-back HVDC power transmission systems have greatly increased. They interconnect large power systems offering numerous technical and economic benefits. The design of AC system filters, however, is not an easy task. Also, filters do not remove all the harmonics for which they are tuned, are costly and have a complicated transient behavior. In this paper a 36-pulse filterless configuration for back-to-back HVDC systems is proposed, whereby harmonics are eliminated within the converter, thus opening the possibility of advantages in aspects of design, reliability and capital savings.